Transmission in various portions of the RF spectrum may be regulated by, for example, the FCC in the United States, and similar agencies in other countries. For example, in the United States a television station may be allocated a channel with a 6-MHz bandwidth in which to transmit their signals. The FCC may have regulations limiting the amount of signal leakage beyond the 6 MHz bandwidth. The FCC may also refrain from allocating adjacent channels within a geographic area in order to provide further buffering against interference. For example, in the Chicago metropolitan area, the FCC allocated channels 5 and 7, but not channel 6. Accordingly, there may be a 6-MHz buffer between the channels 5 and 7. This ensures that interference from other television stations may be reduced. Additionally, the FCC may limit transmission power by a television station. In this way, a local television station may be protected from interference by an adjacent channel in a neighboring city or from the same channel in a distant city.
Some technologies, such as those based on CDMA technology in mobile communications, may allow a plurality of transmitters to transmit in the same bandwidth. However, the use of the bandwidth may be under control of a single entity, and that entity may regulate transmission to reduce interference. For example, a base station may control transmission power levels for each transmitter, or mobile terminal, in a cellular area so that the received power level for each mobile terminal at the base station may be approximately the same. Otherwise, if a rogue mobile terminal transmits at a much higher power level than requested by the base station, the base station may not be able to correctly receive and demodulate signals transmitted by the other mobile terminals.
However, with respect to unregulated RF spectra, such as the 2.4 GHz spectrum shared by Bluetooth devices, WiFi devices, and 2.4 GHz cordless phones, there may not be coordination to reduce interference among devices using the same spectrum. Other devices, such as a microwave oven, may also transmit signals in the 2.4 GHz spectrum that may interfere with the communication devices. If Bluetooth and WiFi devices are being used to transmit data, the effect may be to reduce data throughput due to retransmission of data packets. However, in cases where re-transmission is not supported, for example, voice-over-IP (VoIP), the effect of the interference may result in losing portions of conversation. Similarly, streaming audio and/or video may be affected by interference from other transmission sources.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.